Method of making elastic ply fabric



March 18, '1941- T. G. HAWLEY, .11R

METHOD OF MAKING ELASTIC ILY FABRIC Filed Feb. l2,l 1937 v ATTORNEYS.

INVENTOR. gwe Je atented Mar. 18, 1941 UNITED `STATES PATENT FFICEMETHOD OF MAKING ELASTIC PLY FABRIC tion of New Jersey ApplicationFebruary l2, 1937, Serial No. 125,367

4 Claims.

This invention relates to the method of making an elastic ply fabricconsisting of two textile fabrics having a binding sheet of rubber con-Afined therebetween to hold the fabric sheets 5 yieldingly in a condensedcondition, and to the fabric resulting from the method.

It has been proposed` heretofore to provide an elastic sheet consistingof a stretchable textile fabric such as knitted goods having a rubberbacking applied thereto in an unstretched condition to cause the fabricto contract again after it has 4been stretched. It has also beenproposed heretofore to providean elastic ply fabric of limited stretchand consisting of two textile fabrics united by a rubber sheet or binderwhich secures the two fabrics together with the textile faces out.

In these prior constructions the rubber backing was so applied to thefabric that it would serve to return the stretched fabric to what mightbe regarded as the relaxed or ordinary condition of the fabric beforethe rubber backing was applied thereto, but these rubber backings wouldnot serve'to contract the fabric to a substantial degree past suchordinary relaxed condition to place the fabric in what might be called asuper-relaxed condition.

The present invention contemplates the method whereby an elastic plysheet may be formed by first uniting by a rubber binder two textilesheets which may constitute woven, knitted or other textile fabrics, andthen condensing these united textile sheets so as to place the threadsthereof extending in the direction of stretch in what is herein called asuper-relaxed condition to permit the fabric a substantial range ofstretch. The united sheets may then be heated or otherwise treated toset or vulcanize the rub- -ber binder so as to form an elastic sheetbetween the two fabric sheets, which elastic sheet normally holds thefabric sheets yieldingly in the condensed or super-relaxed condition.The present invention not only provides a simple and practical method offorming an elastic sheet having a textile fabric at each outer face anda rubber binding sheet therebetween, but alsovserves to provide anelastic sheet having a long range of stretch.

As a result of the present invention the textile fabrics having therubber binder sandwiched therebetween are held by the binder contractedto such an `extent that they are much shorter in length than these samefabrics were before they were condensed. That is, these fabrics are notonly held in a relaxed condition by the rubber binder but they are heldin a condensed or super-relaxed condition so that the fabric may stretcha substantial degree before it reaches what may be regarded as itsrelaxed condition before it was condensed and may then stretch 6considerably further. In order that the fabric may have imparted theretothe maximum range of stretch or elongation it is necessary that thethreads ofthe fabric extending in the direction of stretch be normallyheld in a thoroughly rel laxed or unextended condition. This, as abovestated, is secured by condensing the fabric to place it in asuper-relaxed condition and by providing it with a rubber backingadapted normally to retain the fabric in this super-relaxed 15condition.

The various features of the invention will be more fully understood fromthe following description when read in connection with the accompanyingdrawing, illustrating one good prac.- 20 tical form of mechanism forcarrying out the present method, and also illustrating a fabricconstructed by the method.

In the drawing: l

Fig. 1v is a side elevation of mechanism shown 25 more or lessdiagrammatically for carrying out the present method; and

Fig. 2 isa perspective view of an elastic ply fabric constructed inaccordance with the present invention. 30

In carrying out the' invention, two strips of textile fabric of anydesired width are provided. These strips of fabric may be woven, knittedor otherwise constructed but the fabric, if woven,

preferably has a relatively loose or open con- 35.

struction so that it can be condensed to a substantial degree, in themanner hereinafter pointed out.

In the construction shown in Fig. l, one length A of textile fabric issupplied by the upper roll III 40 4supplied between them or upon theadjacent faces thereof so as to secure these fabrics to- 50 gether andform an elastic or rubber sheet therebetween. In the constructionillustrated, the adhesive binder is applied to the adjacent faces of thefabrics I2 and I3 by the spraying nozzles I4. It will be apparent,however, that other 55 means for applying the binder material to theadjacent faces of these fabrics may be employed.

This binder may be applied to the fabrics I2 and I3 in the form of aliquid, plastic or paste containing rubber. It is found in practice,however, that aqueous dispersions of rubber such as natural latex,preferably containing vulcanizing agents and otherwise suitablycompounded by methods well known in the art, are well adapted for thispurpose.

Should it be desired to coagulate or partially coagulate the latex whensprayed upon the fabric, this may be done by applying a coagulating acidupon areas of each fabric before such areas arrive at the nozzles I4.'Ihis coagulation may ybe desirable to avoid excessive penetration ofthe latex into or through the fabric to the opposite face thereof and todecrease the water absorbing properties of the rubber film. After thelatex or other binding material containing rubber has been applied tothe fabrics I2 or I3, it may be desirable to dry this binding materialto some extent and this may be done by subjecting the sheets I2 and I3to the action of heated coils I5 or the like, .or a fan may be used forthis purpose.

The drying at this time however should not be suiiicient to render theserubber covered faces of the fabric non-tacky before they are broughttogether, and if it should be found thatthe rubber faces to be unitedare too dry for satisfactory adhesion a thin lm of fresh latex may' besprayed over such faces. It is important that `these rubber surfaces bein the proper condition as they reach the uniting rolls to be described,so that they will adhere together to `form an integral union withoutcausingthe latex to penetrate through to the outer face of the fabric.It is also important that the latex treated fabrics be in a moistcondition when they are subjected to the condensing operation for thesefabrics will not condense properly unless damp.

The fabrics I2 and I3 after they have the rubber binder .applied totheir adjacent faces may be led between the slightly spaced rolls I6,which serve to bring these fabrics close together before they aresubjected to the condensing action that forms an important stepincarrying out the present method. The word condensing is herein used todesignate the treatment of the fabrics I2 and I3 so as to place thethreads thereof extending in the direction of stretch in a thoroughlyrelaxed condition, or what may be better defined as a super-relaxedcondition. It will be apparent that if the elastic ply fabric of thepresent invention is to have a relatively long stretch, then the textilethreads extending longitudinally of the fabrics I2 and I3 will need tobe in a super-relaxed condition when the elastic ply fabric is in itsnormal contracted condition. As the two fabrics I2 and I3 are forcedtogether ythe rubber coating or layer deposited upon each and I3comprises the elastic belts I3 and I9.

These belts may constitute endless sheets of rubber each having a widthequal to or greater than the width of the fabric to b e condensed, orthese elastic belts may be formed of woven elastic webbing. When thebelts I8 and I9 are used to condense woven fabrics I2 and I3 it isimportant that constant width belts be Used; that is belts that will notcontract width-wise as they stretch longitudinally, and expandtransversely as they contract lengthwise, for it is found that if it isattempted to condense woven fabrics between belts that expandtransversely as they contract longitudinally the woven fabrics will tendto tear under the transverse stretching action or the fabric will not becondensed satisfactorily.

The condensing belts I8 and I9 in the construction shown pass around thepositively driven rolls 20 and 2I and about the idler rolls 22 and 23,and the positively drivenrolls 20 and 2I are preferably provided withthe pinch rolls 24. The rolls 2| are operated at a slower peripherialspeed than the rolls 20 to thereby tension the portion of each belt I8and I9 passing about the idler rolls 22 and 23, and to relieve thetension upon the portion of each belt extending from the roll 20 to theroll 2| and forming the belt runs 25 and 26.

'I'he means illustrated for holding the runs 25 and 26 in firm, grippingengagement with the elastic fabrics comprises the caterpillar belts 21and 23 having the transversely extending slats or bars 29. These beltspass around and are operated by the rolls 30 Aand 3| to travel at thesame surface speed as the rolls 20, and shouldbe maintained in a tightlystretched condition, 'Ihe arrangement is such that the caterpillar beltswill exert a firm, gripping pressure upon the belt runs 25 and 26 lyingtherebetween. The pressure is greatest adjacent the rolls 30 butdecreases in the direction of travel to permit the stretched belts tocontract gradually therebetween so as to condense the fabrics I2 and I3.

As the ply fabric lies between the caterpillar belts 21 and 29 it shouldbe subjected to the heating action of the heaters 32 in order to setand/or partially vulcanize the rubber sheet I1 suiliciently to cause itto retain the fabrics I2 and I3 in the condensed condition before thesefabrics arev released from the pressure of the condensing belts. Finalvulcanization of the rubber sheet I1 may be secured by passing the plyfabric between the heaters 33, but if it is desired to avoid subjectingthe belts I8 and I9 to the action of these heaters 33 they may be placedbeyond the range of these belts, whereupon this finished ply fabric maybe wound upon the roll 34 in an untensioned condition, ready for themarket or any desiredl subsequent treatment.

' It should be noted that the rolls 20 are spaced some distance apart,the effect of this being that if any contraction in the belts I3 and I9occurs, between these rolls 20 and the rolls 30, this contraction willnot affect the fabrics I2 and I3 since these belts do not grip thefabrics I2 and I3 until they are subjected to the confining pressure ofthe slats 29 of the caterpillar belts 21 and 28. Since however the rolls20 and caterpillar belts 21 and 28 travel at the same surface speed noappreciable contraction in the portions of the belts just mentionedshould occur. Inorder to facilitate the contraction of the belt runs 25and 25 relative to the caterpillar belts 21 and 29 it may be advisableto apply powdered talc or the like to the faces of the belts I8 and I9which contact with the slats 29.

It will be seen from the foregoing that through the present method thetextile fabrics I2 and I3, are united by a rubber binder and thencondensed to form a multiple elastic fabric having a single rubber sheetI1 formed between the textile fabrics and molded to the inner faces ofsaid aaaacea fabrics. t will also be seen that this is readilyaccomplished in a continuous operation.

The fabrics I2 and I3 are shown in Figure 2 as knitted fabrics united byand normally held in a condensed or super-relaxed con-dition by therubber sheet Il. The ply fabric thus produced may have a substantialdegree of stretch, for example or more.

Practically any textile fabric that has a sufficiently open or looseconstruction to permit the same to be condensed, by placing thelongitudinally extending threads in a super-relaxed condition, may beformed into an elastic ply fabric in accordance with the presentinvention, but as above pointed out when a woven fabric is condensed itshould not be subjected to Aa transversely expanding action that tendsto tear the fabric, or cause the belt to creep relative to the fabric.

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

l. The method of making an elastic ply fabric comprising applyingaqueous dispersion of rubber to the surfaces of two textile fabricsheets, adhering said sheets together with the adhesive binder formedfrom said aqueous dispersion of rubber, engaging the outer surfaces ofthe textile sheets with stretched elastic surfaces and pressing saidtextile sheets together between, said elastic surfaces, releasing atleast some of the tension on said elastic surfaces while in engagementwith the outer surfaces of the textile sheets and thereby condensing thetextile sheets by the contraction of said elastic surfaces, and heatingand drying said adhesive binder while said textile sheets are retainedin engagement with said contracted elastic surfaces and held thereby inthe condensed condition to some extent and until said binder is impartedsufficient strength to retain said textile sheets in the condensedcondition.

2. The method of making an elastic ply fabric comprising applyingaqueous dispersion of rubber to the surfaces of two textile fabricsheets, partially drying said aqueous dispersion of rubbei', adheringsaid sheets together with the adhesive binder formed from said aqueousdispersion of rubber, engaging the outer surfaces of the textile sheetswith stretched elastic surfaces and pressing said textile sheetstogether between said elastic surfaces, releasing at least some of thetension on said elastic surfaces while in engagement with the outersurfaces of the textile sheets and thereby condensing the textile sheetsby the contraction of said elastic surfaces, and heating and drying saidadhesive binder While said textile sheets are retained in engagementwith said contractedl elastic surfaces and held thereby in the condensedcondition to some extent and until said binder is imparted sufcientstrength to retain said textile sheets in the condensed condition.

3. The method of making an elastic ply fabric comprising introducingbetween two textile fabric sheets natural rubber latex containingvulcanizing ingredients, engaging the outer surfaces of the textilesheets with stretched elastic surfaces and pressing the textile sheetstogether, releasing at least some of .the tension on said elasticsurfaces While in engagement with the outer surfaces vof the textilesheets and thereby condensing the textile sheets by the contraction ofsaid elastic surfaces, heating and drying said latex to form an adhesivebinder while said textile sheets are retained in engagement withsaid-contracted elastic surfaces and held thereby in the condensedcondition to some extent and until said binder is imparted sufficientstrength to retain said textile sheets in the condensed condition,removing said elastic surfaces from engagement with said textile fabricsheets, and Vulcanizing said binder to produce an elastic sheet ofrubber which is bonded to the textile fabric sheets.

4. The method of making an elastic ply fabric comprising the steps oftreating two textile fabric sheets With a coagulant, spraying one sideof each of said sheets with natural rubber latex containing vulcanizingingredients, partially dry- 4ing said rubber latex, placing the sprayedsurfaces of the textile sheets together, engaging the outer surfaces ofthe textile sheets with and pressing said sheets together betweenstretched elastic surfaces, releasing at least some of the tension onthe stretched elastic surfaces while in engagement with the outersurfaces of the textile sheets and thereby condensing the textile sheetsby the contraction of the elastic surfaces, heating and drying saidlatex to form an adhesive binder while said textile sheets are retainedin engagement with said contracted elastic surfaces and held thereby inthe condensed condition until said binder is imparted sufficientstrength to retain said textile sheets in the condensed condition.

THOMAS G. HAWLEY, JR.

